/**
 *   Licensed to the Apache Software Foundation (ASF) under one
 *   or more contributor license agreements.  See the NOTICE file
 *   distributed with this work for additional information
 *   regarding copyright ownership.  The ASF licenses this file
 *   to you under the Apache License, Version 2.0 (the
 *   "License"); you may not use this file except in compliance
 *   with the License.  You may obtain a copy of the License at
 *
 *       http://www.apache.org/licenses/LICENSE-2.0
 *
 *   Unless required by applicable law or agreed to in writing, software
 *   distributed under the License is distributed on an "AS IS" BASIS,
 *   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *   See the License for the specific language governing permissions and
 *   limitations under the License.
 */
package com.qlangtech.tis.db.parser;

import java.util.ArrayList;

/**
 * @author 百岁（baisui@qlangtech.com）
 * @date 2020/04/13
 */
public class TokenBuffer {

    private int currentPosition;

    private final ArrayList<Token> tokenList;

    private final int tokenSize;

    public TokenBuffer(ArrayList<Token> tokenList) {
        this.tokenList = tokenList;
        this.tokenSize = tokenList.size();
    }

    public Token nextToken() {
        if (currentPosition >= tokenSize) {
            return null;
        }
        return this.tokenList.get(currentPosition);
    }

    public Token popToken() {
        if (currentPosition >= tokenSize) {
            return null;
        }
        return this.tokenList.get(currentPosition++);
    }

    public void resetCurrentPosition(int savePosition) {
        this.currentPosition = savePosition;
    }

    public int getCurrentPosition() {
        return this.currentPosition;
    }
}
